Intro

Basically, it occurred to me after reading another thread on
IBL (Image Based Lighting) that I, personally, don't really understand
UberEnvironment2 (UE2 hereafter) (included in DS3A and DS4A and higher) as well
as I should.

So this isn't really a tutorial. This is more of a journal of my journey of
collecting what I DO know, what I think I know and trying to learn more.

The first thing I know? Well, I've already said it. There's a lot about UE2
that I don't know.

I also know that I can get some amazing results out of it but often there is a
lot of trial and error and when I find something I like I tend to over use it
causing much of the output of many of my renders to have a feeling of
"uniformity" even if the content is quite different.

So here we are, chronicling my effort to learn more about UE2 and yes, this is
pretty much how I learned almost everything I know about DAZ Studio. Reading
here, sharing here and good ol' trial and error.

Please feel free to ask questions, make observations, correct my
misunderstandings, etc. as I start this journey of a deeper understanding of
UE2 in DAZ Studio. I will primarily be using DS3 for this, but everything still
should apply for DS4 users.

Journey 01: The Beginning

To start things off, what I've done is I put together a
fairly simple scene. Most importantly though I created a ground plane. I wanted
to see shadows and we've got to have something for shadows to land on. Then I
tweaked the surface of the plane a little bit. I changed the specular color to
255 255255 and the
glossiness to 35%. I also reduced the Ambient strength to 0%. This gives me a
slightly better pallet for shadows to land on and should not introduce much in
the way of color influence over shadows / bouncing lights etc. I also created a
sphere primitive and did basically the same thing, except I also changed the
diffuse color on its surface to 255 0 0 (bright red).
I did this to give some extra contrast. I probably should've used multiple
primitives but that was boring so I added the Coalition Claymore suit to the
ground so it'd be more entertaining.

The next thing I did was add UE2 to the scene, applied the Set HDR KHPark preset and then the 3 high quality preset.

Before I went any further, I thought, okay, well, let's see what each of the
various Environment Modes on UE2 do. So I'm going to go through them all and
talk a little about each as I go.

Ambient Mode

So the first mode I chose was, intentionally the most basic
mode UE2 offers. "Ambient (No Ray Tracing)". As one should gather
from the name, this mode offers no shadows, no occlusion, nothing but an
overall "ambient" light.

Rendering the scene in this mode demonstrates that fairly
clearly.

Total Rendering Time: 7.48 seconds

Now, why might I use this mode? Well, it's durn
quick. But really, by itself it isn't all that useful. The way I foresee using
this mode would be at a greatly reduced intensity as a supplement to additional
lighting. You could easily use it to provide "ambient light" for indoor
scene which is notoriously difficult to do using traditional lighting. Perhaps
even subtly shifting the light color towards a lighter gray or other color as
my suit the needs of that individual scene.

It should be noted, however, that even in "Ambient Mode" because I
have applied an Environment Map the light has become ambient AND directional.
Look at the red sphere in the foreground. It should be fairly easy to see what
impact the environment map has had on the way the light is cast over the scene.
Where I to rotate the UE2 object, that "hot spot" would also move.

Occlusion with Soft Shadows Mode

Next, is the first "Occlusion Mode" or
"Occlusion with Soft Shadows". What is Occlusion? Well, without
getting TOO technical, ambient occlusion determines which areas of geometry are
bright and which are dark (occluded). It does this by bouncing light off the
object and light that makes it back to the camera makes an object brighter.
Light that doesn't makes that part of the object darker.

Now, soft shadows... We know that there's another Occlusion mode (Directional
Shadows) so what does Soft Shadows mean? Well, effectively it means
non-directional. This means that the Environment Map we've specified WILL NOT
affect the 'input' of the light when calculating what is occluded.

So here's what the same scene looks like with Occlusion w/Soft Shadows set as
the Environment Mode.

Total Rendering Time: 1 minutes 14.18 seconds

Now, once again, let's look at the red sphere. The "Hot Spot" of
illumination is still there. You can clearly see what direction the light
"appears" to be coming from... Now look at the plane around each
object. You have a fairly uniform shadow (occlusion) around / under everything.
It looks pretty good, but given the obvious light direction, it doesn't look
very realistic does it?

Now, how and why would we use this mode? Well, much like Ambient Environment
Mode, I can see this mode being useful with "helper lights". In fact,
I tend to use this mode (without an Environment map) in almost all my out door scenes. This gives a reasonable approximation of a
more global lighting setup, leaves the directional shadows to fixed,
traditional lighting and, well, provides occlusion globally instead of per
surface but (without a map) you don't have to worry about aligning the
Environment map with the traditional light setup. Handy. Although, not terribly
accurate as I've mentioned.

Occlusion with Directional Shadows

Next, is probably the most commonly used mode (since that's
how it loads by default) of UE2...

Occlusion with Directional Shadows. In this Environment Mode, the render engine
takes the trouble to create a much more accurate light source (or light source
with varying intensity perhaps would be a better way to think of it). This
gives use "directional shadows" and "directional
occlusion".

Total Rendering Time: 1 minutes 34.40 seconds

Now we can see that the occlusion matches what we would expect with the
"hot spot" on the red sphere. Things look more like what we would
expect in the "real world."

This is the first mode of UE2 that I (personally) feel can be used without much
in the way of traditional lighting assistance. However, I still tend to add
additional lights to the scene I just take great care to ensure that I line the
"sun" of the environment map up with the direction of my primary
traditional light source.

This is also a good time to bring up the major shortcoming of UE2 in DS3. UE2
in Ambient Occlusion mode does not produce, and in fact, reduces every surfaces
specular response. This tends to make things look muted, even though the
brightness of the scene may be fine. The way to avoid this, in my experience,
is to add a distant light at a low to moderate intensity with an Illumination
Mode of "Specular Only" and align that light to match the primary
direction of the Environment Map you're using with UE2. This effectively
"doubles up" on the specular area and can bring back that depth that
UE2 tends to mute. Often it takes me a few stabs at finding the right strength,
but I tend to start at 30-40% and go up from there. Rarely higher than 75% but
it's happened.

IDL with Soft Shadows

Next, we'll try the first of the IDL modes. IDL or Indirect
Lighting is basically the ultimate step that UE2 can take. It effectively,
combines the Occlusion Modes with an "extra series" of light bounces
(partially controled by Raytrace
Depth on your advanced Render tab, but also controlled by the Maximum Trace
Distance on the Parameters tab with UE2 selected).

This mode uncovers one of the biggest flaws with the basic Occlusion modes...
Do you expect the soft shadows here to have the same issues they have in
Occlusion Mode? You should, because they do... however, that's not the issue.
Let's look.

Total Rendering Time: 19 minutes 35.61 seconds

Now, isn't that interesting? Can you spot the difference between this render
and the Occlusion with Soft Shadows mode render? I'll give you a hint, look at
the red sphere. Yup, the "bounce" light has caused the red of the
sphere to "reflect" onto the white of the plane. This mode much more
closely resembles the way the "real world" works... However, the lack
of direction kind of ruins it.

Still, I would use this mode pretty much the same way I would use Occlusion
w/Soft Shadows.

IDL with Directional Shadows

Now, let's look at the IDL w/Directional shadows mode...

This is it... This is the mode where it all comes together and things look
fantastic. At least I think so. We still have the specular problem but now
shadows makes sense, occlusion looks accurate, and the bounce gives us the
color blending that our minds have come to expect...

Total Rendering Time: 22 minutes 38.30 seconds

All of that came at a price though. The scene that took 7 and half seconds to
render at Ambient Mode and just over a minute in Occlusion modes... took over
22 minutes to render in this mode. Keep in mind that there are no hefty transmaps, reflections or much in the way of
"traditional" things that cause "render time increases" in
this scene. Yikes. You definitely pay for that extra realism.

All in all though, I think this is a mode of UE2 I need to really explore as it
seems to create the most realistic results we've seen thus far.

Bounce Light (GI) Mode

But wait, there's still one more mode... "Bounce Light
(GI)". Do not confuse this with true Global Illumination. It isn't. This
mode is what is ADDED to the Occlusion Modes to generate the IDL Mode.

By itself this mode does not appear to be very useful at all. However, it looks
like it will work nicely if you supplemented it with traditional lighting. This
would give you the benefit of color bouncing without the added penalty of
Occlusion. This would work well if you were using Surface based occlusion
(i.e., UberSurface, Elite Human Surface Shader or pwSurface).

For the sake of completeness, here's the same scene above, no additional
changes made, other than the Mode using the Bounce Light mode. Note you can see
the color bounce onto the area of the plane around the red sphere, but the
shadows are terrible. I believe this is because there's no "real"
light source and if there was, the spottiness would go away.

Yikes. I'm hoping that's because it had to deal with
the situation of not having a primary light to work with. Even the omnifreaker UE2 documentation states specifically that this
"method is designed to be used to enhance traditional lighting scenes.
When using this mode, spotlights, point lights, etc should be the main source
of light."

I'll have to experiment with that some more.

I think that's a good start to the journey. We've seen what
little I know and we've seen what the various Environment Modes do.

Journey 02: Map Controls

Alright, as I said at the end of the first lesson we're
going to talk about the Map Controls in this lesson. There are only two of
different map controls (Saturation and Contrast), but it may or may not be
clear what they do.

So we're going to take the trial by fire method and see what happens.

I've created a new scene for this one, this time only using primitives and I
loaded UE2, set high quality, set the environment mode to IDL w/Directional
Shadows and click render. That's where we'll start...

I've added some arrows to each image to help demonstrate what I am observing in
each setting.

So we can see a pretty clear specular response on each
item... the directional shadows, the occlusion near the ground plane as well as
the color bounce we'd expect from IDL.

Nothing new here. For best results following the rest of this, full view the
image above (click on it) and save it out to a folder somewhere. You're going
to want to save each image so you can cycle back and forth through them
clearly.

Name this first image, something like "00a IDL Direct 100 Sat 100
Con.jpg"

Map Controls: Saturation

The next image, I've reduced the saturation to 50%. What
this actually does is reduce the impact of the COLOR on the HDRI Map. Part of
what this seems to do is make the specular response larger, but what I believe
it actually does, is simply create less shadow.

Cycle through those a few time in your favorite image
browser... You can watch the effect pretty easily. What it's really doing, as I
mentioned before is affecting the saturation of the color in the HDRI map. This
works pretty much like Image Saturation Control in your favorite image editing
software. Reducing the saturation to 0% effectively makes it grey scale. This
has a fairly big impact on how the rendering engine determines what is casting
light and what isn't and I believe is what causes the overall
"decrease" in the intensity of the shadows (how dark they are)
because more things are being considered as light sources.

So I think I understand what Saturation does, though the
when and how of its application is still something I'm considering. I think,
ultimately, that you'd probably choose to reduce the saturation if you found
the results of your Environment Map to be too harsh. Lowering it would create a
smoother more balanced image.

Map Controls: Contrast

So, given how Saturation works, what about Contrast? How
will it work I wonder?

The first thing to note is, whoa, what happened to the color
of the plane? It's definitely more grey. Why? Also, look at what happened to
the specular-esque shading on each of the primitives?
It got smaller, or at least that's what appears to happen.

Now one more for image for though: "01c IDL Direction
100 Sat 000 Con.jpg" which, predictably, is at 0% contrast.

So wow, okay, that's pretty strange stuff! Honestly, I'm a
bit lost at this point as to what's going on... the plane got darker, all
apparent specular response everywhere is gone and we can't even really see the
edges of the objects as they're in shadow. How bizarre is that, eh?

So what happens when lower the contrast on an image in your image editor? Well,
that's really kind of hard to describe too isn't it? We're not affecting the
luminosity, we're not affecting the brightness, but we are, I don't know how to
say it really, perhaps everything that isn't white and isn't black moves closer
to the middle. Pure white and pure black don't seem to change, just the things
in between. This again would have the affect of creating an HDRI map that had
FAR more areas that would apparently emit light, but it would leave any area
that was actually black alone so those would still be "dark" areas in
the map... That's my hypothesis anyway...

Map Controls: Mixing Experiments

To see what would happen... I mixed less the above settings.

We already know what 100% and 100% look like, as that was the first image we
compared against... So what does 50/50 look like?

Well, here it is... 02b IDL Direct 050 Sat 050 Con.jpg

Now this is particularly an interesting one. There's a very
"soft" feel to everything. I rather like the effect and I could see
potential uses for it perhaps with 75% contrast instead of 50%, and with soft
shadows instead of directional shadows... I think it would make a very cool
lighting effect where the primary light source was intended to be nearly
omnipresent (think a cave with bio-luminescence or some such)...

Personally, I can't really see the difference between that
and 100% saturation with 0% contrast. I think that the contrast setting is
overwhelming the effect of the "grey scale" nature of the saturation
setting and the net results and so close that at least my eyes can't tell the
difference.

Map Controls: Final Thoughts

So what did I learn about map controls? Well, even though I
didn't show it one thing I learned is that 0% Saturation and 0% Contrast is NOT
the same as no Environment map.

What else did I learn?
1) Reducing the Saturation of a map can increase the overall "luminosity"
of the map. I don't want to say brightness, because that'd be the intensity
control... it makes more areas of the map be treated as light emitting.

2) Reducing the Contrast of the map, keeps "obvious light sources"
and "obvious shadows" but pretty much softens the impact of the map
as a whole.

That's what I've taken away from all that anyway.

What can you infer from these results? What did you learn?

Next we'll go over the "non-quality" portions of the Ray Tracing
section. Those being "Occlusion Strength" and "indirect Lighting
Strength"... After that will be a brief discussion on the remaining
parameters which are all related, in one way or another, to what we would call
the "quality" settings.

Side-Track: Intensity vs. Contrast:

Muon Quark asked: So I wonder what
would happen if you turned down the intensity of the light and used 0%
contrast. If you turned the intensity down far enough, would it make the
objects appear to glow? And if you also used a high ambient setting on the
object, would that help with the glow effect? I think I will have to experiment
with that today.

My theory at this point: I believe you will lose the light
"bounce" with a lower intensity thus reducing / removing the color
bounce effect.

Testing showed:

Turning down the intensity of the light along with the
contrast really took alot of light bounce out of the
scene. First one was normal settings. 100% contrast and intensity on the ue light and no ambient settings for the sphere. I used
Hyde Park with 5XHI settings.

Second one is with contrast and intensity of the light down
to 50% and I added an ambient setting to the sphere of 50% using 255/255/255.
It sorta made the sphere glow but turning down the
contrast AND intensity of the light, you really lose a lot of bounce.

Raytrace Settings: Occlusion Strength

So, we know what occlusion is right? Remember that it is
basically a way of determining how much light a surface receives. It's
calculated by projecting light (or bouncing it if you prefer) and seeing how
much of that light makes it to the current camera.

So what do you think Occlusion Strength does?

My guess, is that the lower the Occlusion Strength the more closely UE2 will
behave to being in Ambient Only mode. In other words, 0% Occlusion SHOULD be
the same as Ambient Only mode. That is just a guess. So let's find out, shall
we?

For this experiment I've created several primitives, gave them colors in the
diffuse channel, made sure their ambient channel strength was set to 0%. I also
set their specular glossiness to 35%, specular color to pure white, and
specular strength to 100%. Then I dramatically upped the quality of the UE2
rendering parameters because I wanted the occlusion and shadows to be ultra
clear but we'll cover that later. UE2 is set to IDL w/Directional Shadows Mode
using the Park Environment map. I've rotated the Park Environment slightly as
shown in the first capture (hint, unhide hidden parameters, unlock the scale,
translation sliders on the UE2 Environment Sphere sub-prop and you can Scale /
Move it as I've done so you can see where the HDRI map light source will be.
Also make sure you rotate the main UE2 object not the Environment Sphere).

Okay, so here's the render of the above scene with Occlusion
Strength set to 100%. I've attempted to identify what each effect on the scene
was going to be.

Now, the same scene with Occlusion Strength set to 0%...

Did you expect the Shadows to the "back left" of
each object to disappear? I didn't! I thought THAT was part of directional
shadows, but no, that's directional occlusion! We've also clearly lost our
bounce colorations as well. You can see it is missing all over the white plane,
but also as bounce on the torus by observing how large (or small) the shadow
is.

Very interesting.

So it looks like this might be a good control to use if you find your
"color bleed" is too strong, though I doubt one would ever take it to
0% like I have in the example above.

Raytrace Settings: IDL Strength

So I went on to test what IDL Strength does... My guess is
that this time it removes bounce behavior from the light making the IDL Mode
equivalent to the Occlusion Mode.

So again, we start with an IDL Directional Shadows mode (just like above)

Then we reduce the Indirect Light Strength to 0% and
render....

Yup, look at that, all the color bleed is gone but we still
have the directional occlusion / shadows. So just for kicks, I switched the
mode to Directional w/Shadows, re-upped IDL strength to 100% and re-rendered.

I can't tell the difference. Why?Because Occlusion mode (as opposed to IDL
Mode) doesn't create the "color blending" that the IDL strength
parameter is used to control.So
basically, IDL Mode with IDL Strength set to 0% is equivalent to Occlusion
Mode.I think I've nailed what that one
does.Again, I think this time you'd use
it over reduced Occlusion to cut down color response but to keep the wonderful
directional occlusion that looks so good.

Raytrace Settings: Occlusion Color

That brings us to one that should be fairly obvious,
Occlusion Color. Since now we know what each UE2 mode does and how it creates
occlusion (soft being "directionless" as opposed to the obvious
"directional" modes), we can, reasonably expect, Occlusion Color to
tint the "occlusion shadows" based on the color we pick. To be
honest, I've never changed this value before. Shadows are supposed to be black right?

Well, why might we want to do this? I can think of a few Sci-Fi / Magic effect
reasons that might warrant it but what else? How about a fake glow? Cranking up
the ambient will get you something that glows but doesn't cast light... Well,
if you set the Environment Mode to Soft Shadows and the Occlusion Color to the
"color of the light" you're going to get an extra layer of
"fake" color added (as opposed to just bounce) that makes it look
more like light is being cast.

So here's a fiddly bit quicky test I did to see what
would happen using the above theory. Ambient is set to 50% strength and the same
red (255,0,0) as the diffuse color (and later the Occlusion Color).

So, here I've changed the Occlusion Color from 0,0,0 to
255,0,0 and re-rendered.

Not the most convincing "light source" but
certainly an interesting effect!

So another thing you might do with it is change the Occlusion color to generate
interesting / unusual shadow colors. Like those "SciFi"
effects I mentioned earlier. Here's I've taken the multi-primitive scene and
changed the Occlusion Color to 255,0,128.

It's most interesting to look at the results on the green cube since the colors
there are more additive than the yellow, red or orange. Hopefully this gives
you an idea of what you might accomplish.

Journey 03: Other Settings

Now lastly let's talk quickly about the various other dials
there are on UE2 (we won't cover the hidden ones, just the normal ones).

Occlusion Samples - This is a quality knob, but NOT your number one quality
knob. It determines how man times to sample colors
around the current pixel. Much like Pixel Samples does on the advanced render
tab. This helps create smooth color transitions. The "4x high
quality" setting of 128 is really quite high enough for almost everything.

Shadow Bias - This works like Shadows Bias on any other light. It's the
distance, in centimeters to shift the shadows TOWARD the light source to
prevent self-shadowing.

Shading Rate - THIS is the number one quality knob for UE2. This is
functionally equivalent to the shading rate on the Advanced Render tab. In
fact, it OVERRIDES the shading rate on the advance render tab at least as far
as the Occlusion and Light generated by UE2 goes. The 4X Hi quality setting
defaults to a value of 8. This generates the most complaints I see on the
forums... "Even at 4x Hi the shadows are splotchy!". This is because,
as we discussed earlier in the thread that UE2 is best used as an auxiliary
light and not as a stand alone light. For my
"high quality" settings a few renders back, I lowered the shading
rate to 1.00. You can see how much cleaner things look. Expect the same type of
"render time" hit when adjusting the shading rate here. The default
value of 8.00 is generally fine when using other lights with shadows.

Max Error - This is a quality knob. It's also a very interesting one. I had to
do some experimenting and some research to figure out what the heck this is.
Basically, this is the 3Delight Irradiance Max Error value. It determines how
strictly the irradiance (think strength of emitted light from a surface) is
calculated. The short version is, higher values = lower quality = faster
renders. When using UE2 with helper lights, it's probably OK to raise this
value up from the "4x Hi" value of 0.10.

Maximum trace Distance - This isn't a quality knob but it has a HUUUUUGE effect
on how occlusion is handled in the render. Basically this value is another
"distance in centimeters" parameter. It measures the distance between
surfaces to determine if occlusion occurs. So if you were, to say, set the
maximum trace distance to 5 (centimeters) you'll get a very small occlusion
effect. The default value is 500 cm (roughly 16.4 feet btw). Lowering the value
will also significantly decrease render times. It also makes UE2 useful as an indoor
lighting effect. I tend to default to a value of 25 (roughly 1 foot) for indoor
work.

Hope you found all of this useful.

Journey 04: Additional Comments / Questions from the Original Posts

1) Harry Dresden asked:

Q: Have you experimented with intensity
levels when used in conjunction with other lights? I'm thinking this is more
useful for light effects (like IDL) than a main source of light but I'm
struggling to figure out how not to over-light my scenes when using this.

A: Absolutely. That's my "default"
setup. I run UE2 at 45% Intensity and use 2(or 3) pt distant lighting to
supplement it for outdoor renders. I setup the main distant light (key light)
at 60-75% intensity depending on how bright the scene is supposed to be. I
setup a specular boost light (lighting mode specular only) at the same
angle/orientation as the key light. I put it at 45% intensity to offset the
quashing of specular response that UE2 creates, and then I use either a back
light or a bounce light depending on the scene needs. That's usually at 20-50%
for back lighting (depending on how much "rimming" I want) and 20-30%
for bouncing. Bounce light is roughly at 90 degrees rotational offset from the
key light and at a VERY shallow angle (like no more than 15%). Oh and another
trick... each additional distant light needs a "higher" shadow
softness percentage than the previous one. If you don't do that you'll get
"studio shadows" where you see shadows running off in every
direction. However, if you DO make them softer than the last they'll layer
almost invisibly.

That's also what I do most of my "DS MAT" development in, except in
the latter case I also make sure that all the lights are set to pure white.

You can grab a light preset that I saved out if you just want to load them by clicking here. Just unzip them to a DAZ Studio Native
content directory and look for them at ~\Lights\AMR\AMR UE2 Presets\Pure White
for MAT work.dsa

2) SiliconAya asks:

Q: With indirect lighting is there
a reason why it's so slow? With Poser 8/pro 2010 rendering a pin-up kind of
scene with IDL at worst doubled the render time, but generally only added a
minute or 2, with DS4 and UE2/UberSoftLightKit at
best it increases render time by 20 or 30 times and often a lot more. Last time
I tried IDL I gave up after 30 minutes with nothing being rendered, when the
same scene rendered in about 2-3 minutes without IDL turned on.

Is it a problem with UE2, DS, the way DS uses 3Delight or a combination of all
of them?

I'm thinking it isn't a problem with 3Delight itself as it's such a high-end
commercial grade renderer and so well used in industry, but I guess it could
be.

A: Yeah, it's partly 3Delight
(which does not handle transparency very efficiently) and partly a function of
how UE2 is just a light providing global Ambient Occlusion, Raytracing
w/Bouncing. That's three complex sets of math that have to be dealt with. One
trick to make IDL faster is to lower the Maximum Trace Depth (how far out raytracing / bounces / occlusion must be calculated).
Another is to use UberSurface to exclude unnecessary
items from Raytracing / Occlusion.

FWIW: 90% of my "final quality" renders take 2-3 hours. Another 2-3%
take less than that and the remaining 7-8%? Yeah, they take more. Sometimes
much more.

3) d-username asked:

Q: i did
some test renders and still seeing some grain in the shadow areas, not bad but

IDL w/Directional shadows mode
UE2 preset 4XHi

3Delight Render Settings
Shading Rate: .20
Shadow Samples: 16 a later version i used 64 and it
did not seem to add that much to render time

Questions
- what settings would be best to lower the grain
- do you use extra lights in the IDL mode or is UE2 enough?

A: If you're using UE2 as the only
light, then you need to lower the shading rate on the parameters tab for UE2
itself as the default Shading Rate even at 4xHi Preset is 8.00 which is fairly
high.When using UE2 as a standalone
light source start with a shading rate of 1.00 and go down from there. This
isn't usually necessary if you're using UE2 with helper lights.

4) MrPoser asked:

Q: I have been trying to learn
Uberenvironment2 along with DS4. I am also not real familiar with IBL so I was
wondering if you could talk a little about the color parameter and the
associated map. Looks like the maps are always 2w x h but are there other
restrictions if we want to play with other maps? I have read you can make the
color grey if your render is too bright?

A: Glad to talk about it.

Yes, the standard image map format for all the uberlights
to use as gels is 2w x h. UberPoints, UberSpots and UE2 itself all follow that guideline. I
believe the only other limitation is the standard 10000 pixel limit on DAZ
Studio itself... so the biggest map would be 10000 x 5000. That might be
important or might not. I've never used anything remotely that large myself.
Usually 4000x2000 or less. If the image map was used in Reflections (and IMO it
should be) then the map size would be more important, but as it stands
currently the image map does NOT show in reflections so its quality is of less
importance.

What I can tell you about the Color mask for the image map of UE2 is that it
acts as a filter against the image map. Keeping it grayscale will let you
adjust the intensity (brightness) of the map. Going into colors gets into some
weird fun additive (or possibly subtractive, but pretty sure it's additive)
math. I'd honestly have to experiment with that some. It should be fun though.
Basic premise would be to make, oh, say, a Green Square in a white field. Then
use a Yellow tint on the diffuse color for the map, see if you get blue or if
you get a different green (additive vs. subtractive).

5) Bendinggrass asked:

Q: I read through your work on
this, but I need something much more basic, from the start, on how to even
begin to use lighting in D4.Could you
recommend something please?

A: Old, but still relevant: http://digilander.libero.it/maclean/DStutorial.htm
This tutorial remains one of the best all time tutorials for getting started
with lighting.Everything it contains is
still applicable in DS4.

6) wiseavatar asked:

Q: Anyone getting a disparity
between the preview environment sphere and the actual orientation of the map?

This especially is evident when you want to use environment mapped reflections
and uberenvironment and the sphere as a background.

To clarify I am not rotating the sphere independant
of the light.

A: Here's what I've noticed... the
Sphere that comes with UE2 is oriented correctly. If I used a primitive sphere,
I have to do all sorts of machinations to get it to align correctly.

When I went to render it, I return
the Sphere primitive to full scale (making it 250m in size), then lowered it on
the Y-Axis by -12500 cm (125m) so that it would be centered on the ground
plane. Rendering it with a small reflective sphere in the center initially made
me believe that the sphere was not reflecting the Sphere Primitive (sky dome) because
the Trace distance was too low.This
turned out to be incorrect.The solution
to the lack of reflection was to set the Sphere Primitive (sky dome)'s Ambient
Color to 255,255,255 and Ambient Strength to 100%.

7) cipher_x asked:

Q: I also noticed a parameter to
set Shadow Type to: None, Shadow Mapped or Raytraced.
I tried it and it did render different types of shadows. By default the Cast
Shadow is set to on but the Shadow Type is set to None. Is that the way it is
supposed to be?

A: You have hidden parameters
enabled. The following parameters (and their default values) are not meant to
be altered: